Ten Smart Sensor Technology Trends for IoT Applications

Ⅰ. Sensors and Smart Sensors

A sensor is a device that can detect and measure specific physical quantities (such as light, sound, pressure, temperature, vibration, humidity, speed, acceleration, the presence of specific chemical components or gases, movement, the presence of dust particles, and so on) by converting them into electrical signals. When the sensor detects and transmits data, the actuator is triggered and begins to work. The actuator receives the signal and determines what steps it needs to do in order to act in the environment.

Smart Sensors are smart sensor devices that can sense, gather, judge, analyze, and process external environmental data autonomously. A multi-element integrated circuit with information gathering, processing, exchange, storage, and transmission functions is known as an intelligent sensor. Sensors, communication modules, microprocessors, drivers and interfaces, and software algorithms are all integrated into one system-level device. It offers capabilities for self-learning, self-diagnosis, and self-compensation, as well as perception fusion and flexible communication.

Compared with general sensors, smart sensors have the following advantages:

Self-check, self-calibration, and self-diagnosis: When the power is turned on, the self-diagnosis function does a self-check and uses a diagnostic test to determine if the component is faulty. Furthermore, it can be rectified online according to the time of usage, and the microprocessor compares and verifies the stored measurement characteristic data.

Induction fusion: Smart sensors can simultaneously detect several physical and chemical properties, providing data that more accurately reflects the law of matter flow. The fusion liquid sensor, for example, can monitor the medium's temperature, flow, pressure, and density all at the same time. How mechanical sensors can simultaneously measure three-dimensional vibration acceleration, velocity, displacement, and other parameters of a specific spot on an item.

Smart sensors include information processing functions that can not only rectify various deterministic system flaws through software but also effectively compensate for random errors and decrease noise, resulting in considerably improved sensor accuracy.

High reliability: The integrated sensor system eliminates some of the traditional structure's unreliable elements and improves the overall system's anti-interference performance. It also has the ability to diagnose, calibrate, and save data while maintaining a high level of stability.

High-cost performance: When the accuracy requirements are the same, the cost performance of multifunctional smart sensors is much higher than that of single-function sensors, especially after integrating a less expensive microprocessor.

Diversified functions: intelligent sensors can realize multi-sensor multi-parameter comprehensive measurement, expand the measurement and use range through programming; have a certain adaptive ability, and can change the range of output data according to changes in the detection object or conditions; have digital communication interface function can be directly sent to a remote computer for processing; it has a variety of data output forms and is suitable for various application systems.

Signal normalization: An amplifier normalizes the sensor's analog signal before an analog-to-digital converter converts it to a digital signal. Digital normalizing is performed by the microprocessor in a variety of digital transmission formats, including serial, parallel, frequency, phase, and pulse.

The following factors are mostly responsible for the rise in demand for smart sensors:

The Internet of Things (IoT) and Industrial Internet of Things (IIoT) are gaining in popularity.

Vehicle electrification and intelligence are on the rise.

Wearable consumer gadgets are becoming increasingly popular.

Sensor technologies and the MEMS manufacturing process have advanced.

Smartphones are increasingly incorporating numerous sensors (such as CMOS image sensors)

Industrial automation and smart manufacturing are in high demand.

Smart cities, transportation, and buildings are all becoming more intelligent.

The global smart sensor market is expected to increase at a compound annual growth rate (CAGR) of 18.6% from 2020 to 2027, reaching US$143.65 billion in 2027, according to studies. The automotive industry is the world's largest application market for smart sensors, accounting for around a quarter of all smart sensor sales. The automotive smart sensor market is predicted to increase at a rate of 21.7 percent from 2020 to 2027, according to the projection. Wearable gadgets and healthcare applications will also provide smart sensor growth prospects in the immediate term.

Micro-electromechanical systems (MEMS) accounted for more than half of the market share from a technical standpoint. Nano Electromechanical Systems (NEMS) are predicted to be the fastest-growing product class throughout the forecast period, but MEMS technology will remain dominant. One of the challenges limiting market growth is the fact that equipment with embedded smart sensors will have a shorter service life.

Ⅱ. Top Ten Smart Sensor Technology Trends for Internet of Things Applications

Smart sensors are in high demand due to the rapid growth and popularization of the Internet of Things. To analyze the technical developments of smart sensors in each application field, we've listed the top 10 Internet of Things application scenarios below.

Smart Wearable

Smart Home

Smart City

smart Transportation

Smart Grid

Smart Building

Smart Agriculture

Smart Medical

Environmental Monitoring

Smart Manufacturing

Smart Wearable Device

In many wearable gadgets, the sensor is the central component and the device's key selling point. Smartwatches and smart wristbands, for example, are items designed to measure human health and activity data and are gradually moving in the direction of medical treatment. To enable users to interact with the surrounding environment and virtual content, virtual reality augmented reality, and mixed reality (VR/AR/MR) devices rely on a comprehensive set of sensors (including RGB cameras, inertial navigation, 3D cameras, force/pressure sensors, and so on). Other wearable product categories (such as electronic skin patches, TWS headsets, smart clothes, and so on) are similar in that they all require a core set of sensors to realize the connection between humans and their surroundings.

Processor and memory, power supply, wireless connection, sensors, and actuators are the five major modules in smart wearable devices. Among these, the sensor is the most innovative of the five modules and the "heart" of human-machine communication. Wearable gadgets can now accomplish more accurate data monitoring thanks to developments in sensor technology.

There are many types of sensors integrated into wearable devices, including:

●Gyroscopes, accelerometers, pressure sensors, and magnetometers are examples of motion sensors. Their primary job is to complete motion monitoring, navigation, and human-computer interaction in smart gadgets, and they are commonly seen in wristbands. Users can learn about their running steps, cycling distance, sleep duration, energy consumption, and other sports and body data by capturing and analyzing human actions at any time using the motion sensor.

●Blood glucose sensors, blood pressure sensors, ECG sensors, body temperature sensors, brain wave sensors, electromyography sensors, and other biological sensors are available. Medical electronic equipment, such as blood pressure monitors, is mostly made of this material. Biosensors are used to gather human body signals, and signal processing is performed to complete health warning and illness monitoring activities.

●Environmental sensors: such as temperature and humidity sensors, ultraviolet sensors, particulate matter sensors, gas sensors, pH sensors, air pressure sensors, and other sensors that can be used in PM2.5 portable detectors, masks, portable personal comprehensive environmental monitoring terminals, and other equipment, with environmental data being tested. Environmental monitoring, weather forecasts, and health warnings are all available.

Smart Home

Smart Home is a residential carrier that integrates security monitoring, home appliance control, lighting control, background music, voice control, and home life integration through integrated wiring, network communication, security protection, automatic control, audio and video technologies, and other technologies. Relevant equipment is intelligently networked for centralized management, resulting in a family living environment that is more convenient, comfortable, safe, and energy-efficient.

These smart home devices are inextricably linked to a crucial component: the sensor. Sensors, actuators, control centers, communication networks, and other components make up the smart home system. To gather varied data about the indoor environment, various types of sensors are employed. The following types of sensors are more typically utilized in homes at the moment:

●Temperature sensor: The room temperature can be kept consistent in the smart home. The temperature sensor can alter the temperature in response to seasonal variations or user needs. The temperature sensor can gather temperature data, which can then be sent to the computer system, which can then be sent to the air conditioner via the central control system to achieve smart home temperature control.

●Image sensor: In a smart home system, information can be transferred to the user's mobile phone or computer via PC-side monitoring, allowing for remote monitoring. The image sensor can be utilized for photoelectric conversion in intelligent monitoring. The camera is primarily made up of a CCD or CMOS sensor, which allows for total smart home control.

●Photoelectric sensor: The photoelectric sensor can be used to operate the smart home in its entirety. The light resistance can be used to create an autonomous lighting lamp, and the infrared sensor system can provide convenient house lighting without the need for human intervention. In addition, infrared sensors can be utilized to manage various variables such as faucets, thermometers, and humidity using photoelectric sensors, saving resources and enhancing user delight.

●The air sensor can monitor the monitored environment in real-time for the user. When the safety index is surpassed, the air purification equipment in the home is activated, purifying the air and providing a healthy air environment for the family. To monitor air quality in real-time, the air sensor can be embedded in various instruments and meters related to the number of suspended particles in the air or environmental improvement equipment.

Smart City

A smart city is one that makes use of information and communication technology (ICT) to improve city management and spur economic growth. The connected network (IoT), which can receive, analyze, and transmit data about current circumstances and occurrences, interacts with ICT. Any gadget that makes cities more efficient or accessible, such as mobile phones, smart automobiles, security cameras, and road sensors, is included in the Internet of Things.

Physical and technological infrastructure, environmental monitoring and response capabilities, and smart services are given to inhabitants are the three primary elements of a smart city. There are three layers to a smart city. The first layer is the technical foundation, which consists of a large number of smartphones and sensors connected via high-speed communication networks; the second layer is made up of specific applications, and the conversion of raw data into alarms, insights, and actions necessitates the use of appropriate tools; and the third layer is the city, which is used by both businesses and the general public. Many applications, such as directing people to use public transportation during off-hours, modifying routes, lowering energy and water usage, or using them at different times of the day, can only succeed if they are widely embraced and attempt to change their behavior. Sexual self-care, for example, relieves the strain on the healthcare system.

The three levels of smart cities proposed by McKinsey Global Analysis Agency

The key infrastructure in a smart city is a network of sensors, cameras, wireless devices, and data centers. The sensor, for example, is at the heart of intelligent infrastructure, and it is a hidden but omnipresent feature of the urban landscape, as well as an essential component of any intelligent control system.

Acoustics, lidar, radar, 3D camera sensors, environmental sensors, flow sensors, gas sensors, humidity and temperature sensors, and so on are all examples of sensor networks. The integrated sensor system aids in the creation of a seamless network with applications and centralized platforms. The sensor network set up for one reason (like street lights) can be used for a variety of other linked applications, including environmental monitoring and public safety. This centralized network will save money in the long run since it eliminates the need for several separate complex networks.

To increase their smart functions, future smart cities will primarily use four sensor technologies: electrical sensors, infrared sensors, thermal sensors, proximity sensors, and lidar sensors.

●Electronic sensors are used in environmental monitoring sensors and speedometer sensors, among other things. These sensors are commonly used in smart city networks to perform a variety of activities, including power and current monitoring and problem detection.

●Infrared sensors: Infrared sensors aid in the generation of unbiased data in dynamic and unstable contexts, assisting in smart city decision-making.

●Radar sensors can interpret critical field data using complicated computer data.

●Thermal sensors measure energy distribution properly, while other smart sensors can regulate demand-side energy. As a result, smart grid sensors aid in energy efficiency.

●Proximity sensors and lidar sensors aid in the development of automated vehicle systems, which are necessary for fully intelligent cities.

Smart Transportation

The employment of various intelligent technologies and equipment to promote the digitalization, connectivity, and intelligence of transportation is known as intelligent transportation. A network connection is one of them, and it is critical to the development of intelligent transportation. The Internet of Things may successfully connect all linkages and aspects of transportation, not only enhancing traffic supervision and upgrading transportation services but also improving existing transportation formats.

The use of intelligent transportation systems (ITS) in urban traffic is primarily reflected in microscopic traffic information collection, traffic control, and guidance, among other things, by improving the effective use and management of traffic information to improve the efficiency of the traffic system, primarily through information collection and input, Strategy control, output execution, data transmission, and communication between subsystems and other subsystems. The information collection subsystem collects vehicle and road data via sensors, and the strategy control subsystem calculates the best Plan using calculation methods (such as fuzzy control, genetic algorithms, and so on) and sends control signals to the executive subsystem (usually a traffic signal controller) to guide and control vehicle passage to meet the preset goals.

The sensor, like the human five senses, plays an indispensable role in intelligent transportation systems and has a wide range of applications in numerous domains of transportation. For example, a sensor network made up of wireless sensors has excellent characteristics that can provide an effective means for the intelligent transportation system's information collection and can detect vehicles coming from all directions at an intersection, as well as improve simplified and improved signal control algorithms based on monitoring results. As well as increasing traffic efficiency. In addition, the wireless sensor network can be used in the execution subsystem's control and guidance subsystems, such as upgrading the signal controller to implement the intelligent transportation system's bus priority function. The position sensor can aid in energy conservation, reduction of emissions, and other purposes.

Sensors can provide driving time prediction data in addition to tracking real-time highway conditions. For driving convenience, these data will be shown as a dynamic message sign (DMS) on the highway's top. A big volume of data is also advantageous for transportation planning, offering more useful information for future highway upgrade plans and decisions, and assisting the intelligent transportation industry's construction.

Smart Grid

A smart grid is a grid system that uses information technology to realize energy resource development, conversion (production), power transmission, distribution, power supply, power sales, and power consumption. Accurate power supply, complementary power supply, enhanced energy consumption, and power supply can all be achieved with smart management. Safety, as well as the desire to save electricity. Smart grids have the potential to reduce CO2 emissions, save energy, and eliminate power outages. The terminal power distribution systems and terminal information systems on power facilities are where the majority of the money spent on establishing a smart grid is spent. Sensor networks account for a significant portion of the investment.

According to the IHS analysis, the market for smart grid-related sensors grew nearly tenfold between 2014 and 2021, reaching US$350 million. The development of sensor networks is a critical component of the smart grid transformation. The idea is to include sensors at all levels of the grid's hierarchical structure. The three levels of the smart grid are the perception layer, network layer, and application layer of WSN (Wireless Sensor Network). The perception layer includes two-dimensional code tags and readers, RFID tags and readers, cameras, various sensors, and sensor networks (a self-organizing and self-healing network composed of a large number of different sensor nodes). The perception layer's main function is to sense and identify objects, collect and capture information.

Smart Building

Smart buildings, as opposed to smart homes, refer to non-residential structures such as office buildings, shopping malls, and hotels. These buildings' gadgets are linked to sensors that may offer energy consumption data and make automated decisions to improve operations. A network of sensors collects environmental data as well as information on the building's operation and usage. This data can be analyzed locally or in the cloud (edge computing), or it can be routed to a central BMS system. This data is then utilized to activate automated operations that modify the HVAC system, lighting system, blinds, and a variety of other building equipment.

Buildings can become "intelligent" by establishing cross-interconnections across multiple subsystems using sensors, actuators, and controls. The actual equipment and control devices are analogous to the muscles and brains of a smart building if the interconnection is compared to the skeleton. The ventilation system can be controlled using this interaction between smart components depending on indoor air quality (IAQ) and indoor carbon dioxide concentration. The lighting system can also be adjusted automatically based on other criteria such as the presence of people and the brightness of the indoor environment, reducing energy consumption and improving user comfort and well-being.

Sensors are critical in monitoring the condition of the equipment. Sensors mounted inside or outside the equipment can collect data on a variety of factors that represent the device's working circumstances. Air pressure sensors, for example, are used in HVAC equipment to monitor airflow, current sensors are used in motor drives to measure current, and microelectromechanical systems (MEMS) microphones are employed in sound anomaly and vibration measurement. In real time, these sensors can detect deviations from a specified optimal state.

HVAC equipment is merely given as an example to show how sensors can aid in condition monitoring and predictive maintenance, allowing building owners, renters, and equipment makers to uncover more added value. Related semiconductor solutions and enhanced software intelligence can solve maintenance problems and provide insights for other essential subsystems including elevators, valves, and lighting.

Smart Manufacturing

CNC machine tools, which are widely employed in the equipment manufacturing business, are one of the usual uses of intelligent sensing in the production process. Modern CNC machine tools are equipped with high-performance sensors that detect displacement, position, speed, pressure, and other parameters in real time, allowing them to monitor processing status, tool status, wear status, and energy consumption to achieve flexible error compensation and self-correction. Recognize the intelligent CNC machine tool development trend. Furthermore, the use of vision sensor-based visual monitoring technology simplifies the intelligent monitoring of CNC machine tools.

Smart sensors are also being used more in the vehicle production industry. The three main applications in the industrial field for machine vision based on optical sensing are vision measurement, vision guidance, and vision inspection. Visual measurement technology can ensure that products are qualified in the automobile manufacturing industry by measuring key dimensions, surface quality, assembly effects, and so on; visual guidance technology can improve significantly by guiding the machine to complete automated handling, best matching assembly, precise hole making, and so on. Visual inspection technology can monitor the stability of the automobile body production process, as well as ensure product integrity and traceability, which helps to reduce manufacturing costs.

Sensors are mostly utilized in the high-end equipment business for equipment operation and maintenance, as well as health management. Intelligent sensors in aviation engines, for example, allow the control system to do fault self-diagnosis and fault processing, enhancing the system's ability to deal with complicated surroundings and precise control. A digital twin that can accurately imitate physical entities can be built using intelligent sensing technology, integrated multi-domain modeling technology, and new information technology. This model may represent the system's physical properties as well as changing environmental factors, allowing the engine's performance to be realized. Assessment, fault diagnosis, life prediction, and other functions based on multi-dimensional feedback data sources throughout the life cycle, rapid learning and autonomous simulation in the behavioral state space, predicting the response to security incidents and discovering problems in real-time through the comparison of interactive data between physical and digital entities

In the realm of industrial electronics, smart sensors are used in robotic arms, AGV navigation vehicles, AOI testing, and other equipment for production, handling, testing, and maintenance. Smart sensors are used in a wider range of applications in consumer electronics and medical electronics. Distance sensors, light sensors, gravity sensors, image sensors, three-axis gyroscopes, and electronic compasses are some of the most popular smart sensors found in smartphones. Wearable devices' most basic function is to detect motion using sensors such as a built-in MEMS accelerometer, heart rate sensor, pulse sensor, gyroscope, MEMS microphone, and other sensors. Position sensors, proximity sensors, liquid level sensors, flow and speed control, environmental monitoring, and security sensors are all used in smart homes (such as sweeping robots and washing machines).

Smart Agriculture

Smart agriculture, also known as precision agriculture, can increase productivity with minimal resources (water, fertilizer, and seeds). Agricultural workers began to comprehend the growth process of crops from a microscopic perspective, scientifically preserve resources, and limit the influence on the environment by deploying sensors and surveying and mapping fields.

Precision agriculture employs a variety of sensor systems. The information they provide can be used to monitor and optimize crops as well as to adapt to changing environmental conditions, such as:

●Position sensor: Determines latitude, longitude, and altitude using signals from GPS satellites. Triangulation requires at least three satellites. Precision agriculture relies heavily on the precise location.

●Light is used to measure soil qualities with an optical sensor. The sensor can be mounted on vehicles or high-altitude platforms like drones or even satellites to detect the reflectance of light at different frequencies in the near-infrared, mid-infrared, and polarization spectra. The optical sensor's soil reflectance and plant color data are merely two variables that can be summarized and processed. Clay, organic matter, and moisture content in the soil can all be determined using optical sensors.

●Electrochemical sensor: It can provide crucial information for precision agriculture, such as pH and nutrient levels in the soil. Specific ions in the soil are detected by the sensor electrodes. Sensors mounted on specially constructed "skates" can currently be used to gather, analyze, and map soil chemical data.

●It can measure soil compaction or "mechanical resistance" using a mechanical sensor. A probe is used to penetrate the soil and record resistance using a load cell or strain gauge. Large tractors employ a similar kind of this technology to forecast the towing requirements of ground-engaging equipment. Tensiometers, such as the Honeywell FSG15N1A, can detect the force exerted by the root system during the water absorption process, which is useful for irrigation interventions.

●Soil moisture sensor: It determines the moisture content in the soil by measuring the dielectric constant (electrical characteristics change as moisture content increases).

●The airflow sensor measures the soil's air permeability. The measurement can be done either static or dynamically while in motion. The pressure required to push a set amount of air into the ground at a predetermined depth is the desired output. Compaction, structure, soil type, and wetness are only few of the soil factors that provide distinct identifying traits.

Smart Medical

Medical electronic sensors are a type of sensor with a high value since they are frequently utilized in pricey medical instruments. Medical sensors are categorized primarily based on their operating principles and application forms. Physical sensors, chemical sensors, biosensors, and bioelectrode sensors are the primary categories based on their functioning principles. It is split into implanted sensors, temporarily implanted sensors, external sensors, sensors for external equipment, and edible sensors, according to the application form.

Flexible matrix materials have increasingly entered the medical industry as material technology and electronic technology have progressed, bringing with them the benefits of flexibility, bendability, extensibility, and wearability. Flexible sensors benefit from the flexibility of matrix materials and are therefore compatible with the human body. Wearable and implantable devices both have a high degree of versatility. Smart bandages, smart bandages, flexible oximeters, and flexible wearable ionic humidity sensors can all benefit from flexible sensors.

Implantable sensors are new types of sensors that have arisen in recent years and have the properties of being small, light, and biocompatible. Implantable sensors are typically self-powered and communicate via wireless technologies. Implantable sensors, unlike edible sensors, are usually implanted beneath the skin or in the organs of the user to receive electrophysiological or chemical signals for transmission. The main goal is to correctly monitor physiological signals in order to aid in the development of tailored medication. The problem with standard implantable sensors is that they do not degrade for a long time, causing damage to surrounding tissues or cells in the body and subsequent infection, and surgical removal causes secondary injury as well. Biodegradable implanted sensors have also become popular in recent years.

Environmental Monitoring

The use of sensor technology in environmental detection has two components: a physical or chemical reaction with pollutants in the detected substance to identify whether pollutants are present, and conversion of chemical signals into electrical signals. The use of sensor technologies has enhanced the reliability of environmental detection results significantly. Sensor technologies can be classified into optical sensors and electrochemical sensors based on distinct detection methods; biosensors and immunosensors based on different reaction mechanisms; and liquid sensors and gas sensors based on different detection objects.

The basic premise of biosensors is to use biological materials as sensitive materials, such as functional genes and antibodies, gather biochemical information using signal collecting devices, and interpret the biochemical information translated into electrical signals. As biosensor technology advances, more sensitive materials and sensor elements will aid in the precise identification of additional contaminants in the environment.

Biosensors feature higher selectivity, easier operation, faster test speeds, and more accurate findings than traditional sensors. Biosensor technology is mostly employed in the detection of atmospheric environments, such as:

●Detection of sulfur dioxide. A biosensor is built using an oxygen electrode and liver microsomes carrying sulfite oxidase. By measuring the quantity of sulfite in rainwater, the amount of sulfur dioxide in the atmosphere can be detected. Sulfite can be oxidized by the microparticles in the sensor. It can diminish the dissolved oxygen concentration near the hypoxic electrode after drinking a specific amount of oxygen, drive current variation in the sensor, and indirectly reflect the sulfite concentration after consuming a certain amount of oxygen. This approach is repeatable. In terms of sex and accuracy, there are apparent advantages.

●Detection of nitrogen dioxide A biosensor is made up of a porous gas-permeable membrane, fixed digesting bacteria, and an oxygen electrode. Nitrifying microorganisms nitrify nitrite, giving the biosensor respiratory activity and ensuring the detecting effect's dependability and precision.

Liquid sensor technology, which can detect numerous pollutants in a water body, is used to detect the aquatic environment. Organic and inorganic pollution are the two main types of pollution in the water environment today. The majority of these pollutants are produced as a result of human production and life, and their discharge exceeds the environment's capacity, resulting in water pollution. The use of liquid sensor technology in the detection of water environments is mostly reflected in the following two aspects:

●Heavy metal ion detection: Heavy metal pollution in the water environment is a particularly serious problem. Lead and mercury are two of the most common heavy metal contaminants. These contaminants are hazardous to human health and cannot be eliminated completely. They will have terrible effects once they enter the water body.

●Pesticide residue detection: Pesticides contain a variety of hazardous chemical components. Following the formation of residues, they will enter the human body via food and have a significant impact on the human body. The chemical reaction of cobalt-xylylene blue dye with triazine herbicides in liquid sensor technology detects the presence of pesticides in water bodies.

In the environment, the gas sensor may detect nitrogen oxides and sulfur-containing oxides. The approach is easy to use and has a high detection rate. The basic idea of a gas sensor is that when gas travels through the sensor probe, the probe collects and analyzes relevant gas information, turns the received gas volume fraction into an electrical signal, and analyzes the signal to determine whether there are pollutants.

When using gas sensor technology to detect nitrogen oxides, for example, metal oxide semiconductors are typically employed. Researchers are already proposing more advanced technologies, such as platinum electrode sensors and ion converters. The materials utilized include yttrium oxide and zirconium oxide. Only place them at the discharge port when sensing exhaust gas. The content of nitrogen oxides can be precisely measured after data collection.